This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Single point FCS and RICS was conducted on extrinsically labelled dynamin under different ionic conditions. Also the effect of GTP on the oligomerisation state was investigated. Also single cysteine mutants of dynamin labelled with different fluorescent probes were investigated using single point FCS and RICS. These experiments were performed using 2-photon excitation on either M3 or M5.